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RE: Galvanizing a Spar Hinge

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McMaster Carr has a variety of products that can be put against the faying surfaces.  For starters, check out their moly filled garolite sheets.  When we do similar work in the marine industry, we frequently use ultra high molecular weight polyethylene sheets (UHMWPE) because of their wear and anti-friction properties.  United States Plastic Corp. carries this stuff.


From: Drew Morris [mailto:dmorris(--nospam--at)]
Sent: Friday, February 12, 2010 1:13 PM
To: seaint(--nospam--at)
Subject: Re: Galvanizing a Spar Hinge


Good question.  Depending on how much the spar moves, I can see the galvanizing being worn down.  Can you put some sort teflon washer between the spar and the padeyes?

bill(--nospam--at) wrote:

Let me describe this mechanism.


Imagine a spar made of a length of pipe, with round plates welded on each end to close the pipe - now it looks like a spool. Now, weld a gusset or ear on each end of this assembly, so that they project along the long axis. Put a 1.5 inch hole through each of these gussets.


Now imagine you have embed plates or padeyes anchored into a concrete block, which have TWO parallel gussets welded to the embed, with a gap between the two pltes just a smidge wider than the thickness of the gusset plate on the spar. These plates also have 1.5" holes, so that you can fit the spar gusset between the padeye double-gussets, align the holes, and slip a pin+cotter through the holes.


Voila, you have a hinge.


Now, is it okay if everything is galvanized? Or must you prevent galvanizing deposits on the "faying surfaces" of these plates (both sides of the spar gusset, and the inside of each padeye gussets)?


Comments, please.